Gabrielle-Émilie le Tonnelier de Breteuil

The Marquise du Châtelet, née Gabrielle-Émilie le Tonnelier de Breteuil (1706 - 1749) French mathematician and physicist. The daughter of an important functionary in King Louis XIV’s court, she was well-educated in languages, sciences, mathematics, arts and sports. Barely 20, she married the Marquis du Châtelet and bore him three children, possibly by other men. To educate her children, she wrote a textbook on physics and made a French translation of Isaac Newton’s Philosophie naturalis principia mathematica that is still used today. Her approximation e∼m⁢v2 (the energy e of a moving object is proportional to its mass m times the square of its velocity v) presaged Einstein’s equation e=m⁢c2 by a century and a half.